Hospitals, biological research laboratories and a number of other facilities generate waste materials that may be infectious and therefore cannot be handled in the same manner as ordinary wastes. Bandages, tissues, hypodermic needles and specimen containers are examples of such wastes.
Bio-hazardous wastes of this kind should be stored in closed containers, should not be directly handled by persons and should be sterilized before being disposed of in land-fills or other disposal sites.
Sterilization of such materials by incineration requires costly processing installations because of high fuel costs, pollution problems and other factors. It is simpler and more economical to sterilize the wastes by exposure to steam. Wastes from hospitals and the like are usually compressible and further economies can be realized by compacting the material following sterilization. This enables storage and hauling of greater amounts of the waste in containers and trucks of given capacity and also makes more efficient use of dump-site space.
Prior U.S. Pat. Nos. 5,084,250 and 4,374,491 disclose prior apparatus for temporarily storing, sterilizing and subsequently compacting wastes of the above discussed type before the material is transported to a disposal site. As heretofore constructed, such apparatus typically includes a housing having a sealable internal chamber which can be accessed through a door in the side of the housing when wastes are to be deposited in the chamber. After a sizable amount of such waste has been accumulated, the chamber is sealed, air is evacuated and pressurized steam is admitted to heat the contents to temperatures which destroy biological organisms. The sterile wastes are then discharged from the sterilization chamber and a translatable compactor ram forces the material into the inlet opening of a closed compactor container which is situated adjacent to the apparatus and which, when full, is used to haul the processed waste to a dump-site.
The waste materials are typically contained within disposable plastic bags which initially serve as liners for waste receptacles in the hospital or the like. The contents of the bags are not emptied into the sterilization chamber. The bags are also contaminated waste and are deposited in the chamber with contents intact. The presence of the bags, which may contain much air, and the compressible nature of much of the waste itself results in a low packing density of material in the chamber. This adversely affects operating costs by requiring frequent sterilization cycles and by limiting the amount of waste that is processed during each such cycle. It would be advantageous if the effective capacity of a chamber of given size could be increased.
Sterilization of the waste depends to some extent on the conduction of heat within the mass of waste material as the steam may not directly contact all infectious organisms within the waste. It would be advantageous to provide for a more rapid distribution of heat to all portions of the waste.
It would also be advantageous to facilitate the use of cart dumping machinery for loading wastes into apparatus of the above described kind. Cart dumpers of the known kinds typically lift a cart of wastes and then invert the cart to drop the contents into a hopper or other opening at the top of the waste receiver. The side opening access doors of prior waste sterilizing and compacting apparatus are not conducive to use of such dumping equipment. Moving the access door to the top of the apparatus would enable top loading but would not, in and of itself, increase the effective waste storage capacity of the sterilization chamber.
The present invention is directed to overcoming one or more of the problems discussed above.